Python程式:構建樹並執行插入、刪除和顯示操作
當需要構建二叉樹並執行諸如插入元素、刪除元素和顯示樹的元素等操作時,可以使用定義了方法的類。 定義類的例項,並將其用於訪問元素和執行操作。
以下是相同的演示 -
示例
class Tree_struct: def __init__(self, data=None, parent=None): self.key = data self.children = [] self.parent = parent def set_root(self, data): self.key = data def add_node(self, node): self.children.append(node) def search_node(self, key): if self.key == key: return self for child in self.children: temp = child.search_node(key) if temp is not None: return temp return None def remove_node(self): parent = self.parent index = parent.children.index(self) parent.children.remove(self) for child in reversed(self.children): parent.children.insert(index, child) child.parent = parent def bfs(self): queue = [self] while queue != []: popped = queue.pop(0) for child in popped.children: queue.append(child) print(popped.key, end=' ') my_instance = None print('Menu (this assumes no duplicate keys)') print('add <data> at root') print('add <data> below <data>') print('remove <data>') print('display') print('quit') while True: do = input('What would you like to do? ').split() operation = do[0].strip().lower() if operation == 'add': data = int(do[1]) new_node = Tree_struct(data) suboperation = do[2].strip().lower() if suboperation == 'at': my_instance = new_node elif suboperation == 'below': position = do[3].strip().lower() key = int(position) ref_node = None if my_instance is not None: ref_node = my_instance.search_node(key) if ref_node is None: print('No such key.') continue new_node.parent = ref_node ref_node.add_node(new_node) elif operation == 'remove': data = int(do[1]) to_remove = my_instance.search_node(data) if my_instance == to_remove: if my_instance.children == []: my_instance = None else: leaf = my_instance.children[0] while leaf.children != []: leaf = leaf.children[0] leaf.parent.children.remove_node(leaf) leaf.parent = None leaf.children = my_instance.children my_instance = leaf else: to_remove.remove_node() elif operation == 'display': if my_instance is not None: print('Breadth First Search traversal is : ', end='') my_instance.bfs() print() else: print('The tree is empty') elif operation == 'quit': break
輸出
Menu (this assumes no duplicate keys) add <data> at root add <data> below <data> remove <data> display quit What would you like to do? add 5 at root What would you like to do? add 6 below 5 What would you like to do? add 8 below 6 What would you like to do? remove 8 What would you like to do? display Breadth First Search traversal is : 5 6 What would you like to do? quit
解釋
建立具有所需屬性的“Tree_struct”類。
它有一個“init”函式,用於建立一個空列表。
定義另一個名為“set_root”的方法來指定樹的根。
定義另一個名為“add_node”的方法,該方法有助於將節點新增到樹中。
定義另一個名為“search_node”的方法,該方法有助於搜尋特定元素。
定義一個名為“remove_node”的方法,該方法從樹中刪除元素。
定義另一個名為“bfs”的方法,該方法有助於在樹上執行廣度優先搜尋。
建立一個例項並將其賦值為“None”。
獲取使用者輸入,以確定需要執行的操作。
根據使用者的選擇執行操作。
在控制檯上顯示相關的輸出。
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